Development of a steerable hysteroscope: studies in the baboon.

A steerable fiberoptic hysteroscope was developed with an integrated fluid circulatory system and a channel that can be used either for operative procedures or for the passage of a uterotubal occlusive device delivery assembly. The hysteroscope was demonstrated to be a safe and practical instrument for intrauterine observations, using the baboon as the animal model. Postpartum baboons were used for a majority of the experiments since the cervix of most cycling animals could not be sufficiently dilated to permit hysteroscope insertion. Estrogen-progesterone treatment resulted in softening of the cervix enough to allow hysteroscopic examination in 66 per cent of the animals so treated. Hysteroscopy was performed on 18 baboons. In almost all cases the uterotubal junctions were visualized and appeared as small slits or depressions. Measurements of the mean uterine length, fundal width, normal cervical diameter, and the diameter to which the cervix can maximally be dilated are reported for cycling, hormone-treated, and postpartum baboons.